console.log(3>6); //false
console.log(5==6);//false
console.log(5!=6);//true
console.log(8=='8');//true
console.log(8==='8');//false
console.log(5>'10');//false
//5>'10'  => 5 > 10
//5 +'10' => '5' + '10'  = 510
//5-->53
//1-->49
console.log('5'>'699999');

console.log('张三丰'>'张无忌');//false
//三 19977  无 26080

console.log(10>'3a');
//Number('3a') --> NaN
//NaN  not  a  number
console.log(isNaN(3));//false
console.log(isNaN('3a')); //true
console.log(NaN == NaN);//false





